Whilst googling Retigabine, a Potassium Channel Modulator,I found this list of drugs, with some trials results, that can help T.
In the Potassium Channel Modulator section it says "These results suggest that potassium channel modulators may represent new therapeutic candidates for tinnitus management." A drug called Retigabine is supposed to be the same as the 'Maxipost' cited in the article.
What I started to wonder was; are they not doing proper trials on this drug for T because the drug exists already (and is cheap) so if it does work they wont be able to make enough money out of it? Call me sceptical...